Hi Amelia
Has this "H&S compliance manager" set out the reasons for their opinion that using ladders is "inappropriate"?
If not, perhaps challenging them to justify their position might be your first step BUT who they work for may make a difference to what is an appropriately diplomatic response to their demands.
In general, the WAH Regs (as legislation that WAH has replaced) requires what is reasonably practicable to prevent falls from height.
HSE at Safe use of ladders and stepladders - HSE comment right at the start.
"Ladders and stepladders are not banned under health and safety law.
The law calls for a sensible, proportionate approach to managing risk, and ladders can be a sensible and practical option for low-risk, short-duration tasks, although they should not automatically be your first choice."
This HSE webpage goes on to continue in words to the effect that if work is likely to last more than half an hour then you should probably be looking for an inherently safer place of work.
Now, to be honest I have never taken the "30 minute rule" that seriously not least as some tasks might require 20 minutes up a ladder here, followed by 20 minutes there and so on, where each location might be close to each other and often it might be more sensible to use e.g. a mobile scaffold tower or MEWP and just move the equipment from one position to another.
However, what sounds like banning the use of ladders for VERY short duration work - you say 5 minutes - seems like a very simplistic approach by this "H&S compliance manager".
It is very easy for HSE to remind any duty holder that if it gets to legal proceedings the onus is on the defendant to prove what is or is not reasonably practicable and perhaps this "H&S compliance manager" is taking a similar approach, possibly allied by that popular question "how long does it take for someone to fall?"
....possibly with "and die" tagged on.
Ultimately it is going to be your risk assessment that justifies continuing to do short duration work from ladders, with some or all of the controls that you mention.
Possibly the way to record your risk assessments doesn't help your position.
As example, if you use one of those popular risk matrices with say a scale of 1-5 for Likelihood and 1-5 for Severity/Consequence then if you default to assuming the worst severity you are going to pick a 5 whatever the distance that someone is likely to fall and whatever they are likely to fall onto and/or strike on the way down.
But statistically it is very unlikely that the person will actually fall, and stastically, very unlikely that if they do fall that the outcome will be death.
At Statistics - About HSE statistics HSE says that 138 people sustained fatal accidents at work in the last reporting year.
OK, that sounds like a lot (AND it IS an underestimate as so many fatal and other accidents are excluded from the scope of RIDDOR, e.g. most work-related transport accidents) but say 1000 work-related ACCIDENTAL deaths per year in the UK is statistically tiny compared to the number of hours worked.
[NOTE - FAR more premature deaths per year due to occupational health risks]
You might need to do some sums to justify your use of ladders to somebody with a mindset to ban their use entirely.
So, 138 deaths but not all from falls from height. In the latest year, 50, so 36% of the total.
In "R2P2", HSE suggests that an Individual Risk of Death (IR) of less than 1 in a million per year per worker is in the "Broadly Acceptable" range, so a clue that if you can make the case that the IR for a worker on a ladder for PART of their working hours is down to that sort of probability then you are probably doing all that is reasonably practicable, though you do need to consider all the other risks that each worker faces to work out their individual cumulative IR for the year (or other period in question).
Lots of variables to consider.
Can you get this "H&S compliance manager" to justify their position?